This project is related to the the paper: Chen, X., Huang, Y., Jiang, L. et al. Bilateral upper extremity trunk model for cross-country sit-skiing double poling propulsion: model development and validation. Med Biol Eng Comput 61, 445–455 (2023). https://doi.org/10.1007/s11517-022-02724-8 Please cite our work if you use this code or data.